Seagoing tug and barge construction

ABSTRACT

An integrated tug and barge unit capable of operation on the high seas is produced by providing a twin hull tug boat of the catamaran type and having a horizontally disposed shelf connecting the twin hulls to one another and adapted to receive and retain a projection extending rearwardly from the aft end of the sea-going, cargo carrying barge in firm engagement therewith. The tug boat has a portion of the forward end of each hull shaped to conform with the curvature of a portion of the aft end of the barge hull so that a substantially tight mating engagement therebetween can be provided. Positively driven sliding wedge units or like wedging means are positioned between the barge and tug engagements to insure a tight engagement and to eliminate any relative movement between the tug and barge. Further, positively driven connecting and disconnecting means are provided between the forward end of the barge and the aft end of the tug to draw the tug and barge tightly together and thus prevent the tug from moving aft relative to the barge.

United States Patent 51 3,698,349 51' Oct. 17, 1972 Stevens j 1 i 1 SEAGOING TUG AND BARGE CONSTRUCTION [72] Inventor: John N. Stevens, West Palm Beach,

Fla.

[73] Assignee: Catug Corporation, Fort Lauderdale, Fla.

[22] Filed: June 29, 1971 [21] Appl. No.: 157,875

[52] US. Cl. ..1l4/235 R [51] lnt. Cl. ..B63b 21/00 [58] Field of Search ..l14/235 R, 77 R, 235 A [56] References Cited 1 UNITED STATES PATENTS I 3,398,716 8/1968 Neilson ..1 14/235 R 3,492,964 2/1970 Garcia ..1 14/125 R 3,494,318 2/1970 Katsumura ..1 14/235 R Primary Examiner-Trygve M. Blix Attorney-James P. Jones ABSTRACT a substantially tight mating engagement therebetween can be provided. Positively driven sliding wedge units or like wedging means are positioned between the barge and tug engagements to insure a tight engagement and to eliminate any relative movement between the tug and barge. Further, positively driven connecting and disconnecting means are provided between the forward end of the barge and the aft end of the tug to draw the tug and barge tightly together and thus prevent the tug from moving aft relative to the barge.

10 Claims, 7 Drawing Figures PATENTED um 17 197:

SHEET 1 [1F 2 SEAGOING TUG AND BARGE CONSTRUCTION BACKGROUND OF THE INVENTION A. Field of the Invention.

The general practice in the sea going transportation of cargo that has been followed over the years is to utilize a cargo ship that is designed and constructed for a particular class of goods, such as, for example, a general freight, oil or fuel tanker, collier, or the like. Such cargo vessels are complete vessels containing their own power and propulsion means, complete quar ters for ship personnel, and the like. In recent years, due to reasons of economy occasioned by increased cost of construction and labor cost in operating such vessels, this type of sea going shipping has become less attractive to ship owners.

For example, the construction costs for a cargo ship has increased materially in recent years. Thus, the cost for the building of a complete cargo vessel for the shipment of a particular type of goods, and including all other costs for personnel quarters, propulsion systems and expenditures, represents an initial investment that requires a considerable time to recover.

Another factor that is of paramount interest is that a cargo ship should be efficient in operation and maintenance. With prior cargo vessels, such ships have been relatively fast in moving the goods from one port to another. However, prior cargo ships may be tied up in a particular port for a considerable period of time while the cargo is being unloaded and new cargo taken on. During such a docking, the ships crew is idle unless working at unproductive tasks, such as painting or other housekeeping and maintenance chores.

The present invention is concerned with the elimination of such disadvantages by providing a basic twopart cargo carrying assembly in which one part will be a propulsion section on which the operating personnel will live, and a second separable section which will function solely as a cargo carrying section. In essence, the present invention is concerned with a sea going tug and barge assembly in which the barge carrying the cargo will be pushed by the ocean going tug. Such an assembly materially reduces the initial construction cost of the cargo carrying assembly. Moreover, it will insure that ship personnel will be at productive tasks since the need for prolonged docking to permit unloading and loading is eliminated.

B. Description of the Prior Art.

Considerable activity has been devoted in recent years to the development of sea going tug and barge assemblies which will solve the foregoing and related disadvantages inherent with unitary cargo vessels. The basic initial barge and tub assembly consisted of a barge having a notched or recessed stern which would engage the bow of a pusher tub in detachable relationship in a hinged connection. Such a basic connecting assembly was undesirable since it permitted the barge and tug to pitch and roll independently. This independent movement of the two assemblies made it quite difficult, and oftentimes impossible, to use the tug-barge construction at sea during heavy seas.

Another type of tug-barge assembly that has been employed is the Carport system in which a well extends the major part of the length of the towboat and affords complete bottom support, the center of gravity of the tug being within the horizontal projection of the bottom support. The surfaces of the barge well and the towboat hull have a close fit and the only possible motion of the two hulls with respect to one another is in the fore and aft direction, which, in turn, is resisted with cables or tum-buckles. This connection allows a design in which the lines of the towboat match the lines of the barge and the combination of both has a relatively fair immersed body. However, due to the bottom support of the towboat in the well, the lines of the barge, principally the longitudinal vertical contours, have to be kept very low and close to the keel line, and as a consequence the lines of the stern part of the tug have to have fairly steep longitudinal vertical sections, which is not a very efficient shape for the after body from a propulsion coefficient point of view. Moreover, the Carport system does not meet United States requirements in that each unit, when separated, is not independently sea-worthy and stable on the high seas.

Other tug and barge assemblies have been contemplated or proposed in which various means of attachment of the tug and barge are proposed which endeavor to provide a firm unitary engagement. Representative examples of such assemblies are shown in U.S. Letters Pat. No. 3,345,970 issued to Louis H. DeLong on Oct. 10, 1967, in U.S. Letters Pat. No. 3,362,372 issued to Earl A. Peterson on Jan. 9, 1968, in U.S. Letters Pat. No. 3,417,721 issued to Arthur W. Vienna on Dec. 24, 1968, in U.S. Letters Pat. No. 3,492,964 issued to Emilio C. Garcia on Feb. 3, 1970, in U.S. Letters Pat. Nos. 3,512,495 and 3,550,550 issued to Edwin H. Fletcher on May 19, 1970, and Dec. 29, 1970, respectively, and in U.S. Letters Pat. No. 3,557,742 issued on Jan. 26, 1971, to Reuben M. Gainsby. These foregoing patents are representative only and do not represent all patents that have been issued on ocean going tug and barge assemblies.

Such prior assemblies, while solving certain problems, have presented others. For example, certain of these prior sea going tub-barge assemblies do not insure tight engagement between the units in all types of seas. Moreover, such prior assemblies in many instances are not easily detachable and quite complicated in design, and present problems, therefore, of efficient use. Further, such prior assemblies are not so designed and arranged that they are capable of carrying very large cargoes in all conditions of use.

SUMMARY OF THE INVENTION The present invention eliminates the foregoing and related disadvantages attendant with prior sea going tugboat and barge assemblies. In accordance with the present invention there is provided a twin hull tugboat of the catamaran type and a barge complementary therewith having a new and improved connecting arrangement. Such connecting means will insure a tight locking engagement in all directions under all conditions of use and weather. This is made possible by providing a powered connecting assembly for bringing the tug and barge together and to separate them when desired. Further, a powered wedge unit is provided between the tug and barge in particular areas to insure that there will be no relative movement between the tug and the barge. Moreover, the present invention utilizes a particular supporting and locking arrangement between the mating portions of the tug and the barge.

Another important aspect of the present invention is the provision of a twin hull tug and barge assembly in which the barge can be quite large and the tug is one that is a very deep draft, permitting the use of large, heavy propellors, thereby insuring efficient propulsion of the barge.

Still another aspect of the present invention is the provision of a twin hull, sea-going tug and barge assembly in which the center of gravity will be located over the mating and supporting parts of the tug and barge such that the barge will be so loaded or ballasted that a downward force will be urged on the after end of the barge, thereby insuring a stable and strong assembly.

A further aspect of the present invention is to provide a twin hull tug and barge assembly which can be quickly disconnected at sea and both the tug and barge are seaworthy when separated and disconnected.

Briefly, the objectives of the present invention, in its broadest aspects, are achieved by providing a twin hull tug boat unit having a horizontally disposed shelf connecting the twin hulls together and adapted to receive and retain a projection extending rearwardly from the aft end of the barge in firm engagement therewith. The tug has a portion of the forward end of each hull shaped to conform with the curvature of a portion of the aft end of the barge hull so that a substantially tight mating engagement therebetween can be provided. Positively driven sliding wedge units or like wedging means are positioned between the barge and tug engagements to insure a tight engagement and to eliminate any relative movement between the tug and barge. Further, positively driven connecting and disconnecting means are provided between the forward end of the tug and the aft end of the tug to draw the tug and barge tightly together and thus prevent the tug from moving aft relative to the barge.

BRIEF DESCRIPTION OF THE DRAWINGS The novel features which are believed to be characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and mode of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a top plan view with the barge in broken section illustrating one form of a catamaran or twin hull tug and barge assembly in tight connected relationship;

FIG. 2 is a side elevation of the catamaran tug and barge assembly shown in FIG. 1 with broken lines indicating the connecting arrangement between the two units;

' FIG. 3 is an enlarged fragmentary plan view' of one form of wedging assembly made in accordance with the present invention and which is shown positioned between the respective hull portions of the tug and barge;

FIG. 4 is an enlarged cross sectional view of the wedge assembly taken on lines 4-4 of FIG. 3 illustrating one end of the wedge assembly and the relative positions of the wedge assembly, tug hull and barge hull when the wedge assembly is fully engaged.

FIG. 5 is an enlarged cross sectional view of the wedge assembly taken on lines 5-5 of FIG. 3 illustrating the other end of the wedge assembly and the relative positions of the wedge assembly, tug hull and barge hull when the wedge assembly is fully engaged.

FIG. 6 is an enlarged fragmentary view in side elevation and partly in section illustrating a form of nesting engagement of the projection from the aft end of the barge with the center portion of the tug that may be employed in the present invention, and also illustrating one form of connecting means for positively securing the tug and the barge; I

FIG. 7 is a fragmentary enlarged view taken on lines 7-7 of FIG. 6 illustrating-in detail a form of interlocking between the barge projection and the tug recess.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, a twin hull tug boat, generally designated by reference letter T, and a barge, generally designated by reference letter B, are shown in connected relationship ready for operation on the high seas. The tug T is a catamaran tug which is characterized by having twin hulls laterally spaced from one another forming a slotted area within which the aft portion of the barge will be seated in a manner to be more fully described hereinafter. The barge B, as illustrated, is an oil tanker and the oil carrying compartment is shown in broken section. It is to be clearly understood that the barge B may be of any cargo carrying type or design so long as the aft portion of the barge is constructed in accordance with the present invention.

The tug boat T, as shown, is provided with the usual engine rooms, ship personnel accommodations, and all other conventional equipment necessary for a sea going tug. The tug boat T is a catamaran tug and utilizes large, slow turning propellors, and consequently is generally of a deep draft and powered by heavy duty engines capable of propelling or pushing large, heavily laden cargo carrying barges, tankers, or like units at an effective and efficient speed.

The tug boat T is provided with twin hulls 10 which are asymmetrical or mirror images of one another. It is to be clearly understood that in some instances the twin hulls of identical configuration and contour can be employed. The hulls 10 are laterally spaced from one another forming a slot portion between which the aft portion of the barge B, as shown in FIG. 1, will be seated. The contour of each of the hulls 10 is such that it will conform to the contour of the engaging portion of the projection extending from the aft portion of the barge B, thereby insuring that no forward movement of the tug relative to the barge will occur. It is to be emphasized that where surfaces of the tug and barge are to be in mating relationship with one another, the respective engaging surfaces will be contoured so as to mate with one another as closely as possible.

The center body 11 of the tug extends between the twin hulls 10 at the aft end of the tug and forms a top shelf member adapted to engage the top surface of a rearwardly extending projection of the barge B in a manner to be described more fully hereinafter. The inboard side of each of the twin hulls 10 is provided with support means in the form of a longitudinally extending shelf portion 12 (see FIG. 7) which is vertically spaced downwardly from the undersurface of the center body 11, forming a slot therebetween on the inboard side of each of the hulls 10. This formed slot preferably is tapered in height and has a greater vertical depth at the forward end than the aft end. This configuration will be found to be particularly desirable since it will permit ready engagement of the tug and barge and will aid in the firm locking of the tug and barge hulls together thereby providing relative vertical movement therebetween. The formed slots will receive the side edge of the rearwardly extending portion of the barge B to prevent relative vertical movement between the tug and barge in a manner to be more fully described hereinafter.

The barge B, as illustrated, is provided with a cargo carrying area C with such area occupying substantially the entire barge area. In the illustrative embodiment shown, the bargeB is an oil tanker but it is to be clearly understood that the barge may be any type of cargo carrier, regardless of the form or nature thereof. The only requirement is that the aft end of the barge be so constructed as to be complementary with the forward end of the tug boat.

The aft end of the barge B has a rearwardly extending, horizontally disposed projection member 13 of a design and configuration such that it will be nested between the twin hulls 10 of the tug T in substantially tight engagement. The top surface of the projection 13 will tightly engage the undersurface of the center body 11, with each side edge of the projection resting on the respective shelf portions 12 mounted on the inboard side of each of the twin hulls 10 of the tug T. The projection member 13 of the barge B, when in this locked relationship with the center body I1 and the shelf portion 12, will prevent any relative vertical movement between the tug and the barge.

As hereinbefore noted, forward movement .of the tug T relative to the barge B is prevented by contact between the twin hulls l0 and the aft area and projection 13 of the barge B. The portions of the barge B which will engage with complementary portions of the tug T will be of a contour conforming to that of the mating parts of the tug such that a flush engagement will be insured.

The top surface of the center body 11 of the tug is provided with a centrally mounted connecting assembly which, in conjunction with a complementary connecting assembly mounted on the top surface of the projection 13 at the aft end of the barge B, serves to function as the means to prevent the tug from moving aft relative to the barge during use. Moreover, such connecting assembly will serve to draw the tug and barge together in tight relation when secured together, and will also serve to force the tug aft relative to the barge when the units are to be disconnected.

In the illustrative embodiment of the connecting assembly, an internally threaded rotatable nut 14 is centrally mounted on the top surface of the center body 11 of the tug and is adapted to receive one end of a screw member 15. The other end of the screw member 15 is detachably connected to a mounting member 16 firmly attached to the barge B. The rotatable nut may be motor driven by a motor (not shown) or may be mechanically rotated by a crank or other device (not shown). With this assembly, a rotation of the nut 14 will cause the screw member 15 to move aft, causing the tug T to be positively drawn to the barge. A reverse rotation of the nut 14 will positively force the tug away from the barge.

It is to be clearly understood that the connecting assembly just described is illustrative in character only and represents but one of several types of connecting means readily available that may be employed to retain the tug and barge in tight fore-aft. relationship thereby preventing any relative movement therebetween.

In order to further insure that no relative transverse or vertical movement will occur between the tug boat and barge, a movable wedge mechanism is interposed between the engaging hull portions of the tug and barge. This wedge mechanism is necessitated since a perfect fitting of the tapered sides of the tug and barge recess cannot be obtained because of manufacturing difficulties, and, as a consequence, a means of providing a fixity between the engaging surfaces of the barge and tug must be provided since relative movement of the tug and barge at sea cannot be tolerated. In general, such wedge mechanism will be actuated by a suitable power means, such as, for example, an electric motor, thereby insuring a tight, positive wedging relationship. This wedge mechanism, when fully extended outwardly, will further prevent vertical and transverse movement of the aft end of the'center body 11 of the tug.

For an illustrative embodiment of a preferred form of a movable wedge mechanism, reference is to be had to FIGS. 35 wherein such mechanism and its mode of operation is shown in detail. Reference will be had to a single wedge assembly, but it is to be noted that two or more of such wedge assemblies, as may be needed or required, can be employed. As shown, the wedge assembly is interposed between the outboard sides of the projection 13 of the barge B and the inboard sides of the twin hulls 10 of the barge B.

As shown, the inboard side of each tug hull 10 is fitted with a longitudinally extending recess or channel 18 which is tapered fore and aft, with the greater depth at the forward end. A recess or channel 19, triangular in cross-sectional configuration and complementary with recess or channel 18 in the tug hull 10 is longitudinally positioned on the outboard vertical side of the projection 13 of the barge B. This recess or channel 19 is not tapered, being of constant cross-section throughout its length.

A wedging member 20, which is generally trapezoidal shaped in cross-section and tapered longitudinally, is positioned within the recess or channel 18 with the triangular portion of the wedge member 20 seated in the recess or channel 19 of the projection 13 of the barge B. To effect the movement of the wedge member 20, an operating shaft 21 is connected at one end to the wedge member 20, with. the opposite end of the shaft connected to a suitable prime mover (not shown).

To effect the desired wedging between the tug T and the barge B, the prime mover will force the wedging member or members 20 in the channels or recesses 18 and 19 of the tug and barge respectively. When the operating shaft 21 is extended at its outermost position the wedge members 20 will be disposed firmly between the mating areas of the tug and barge and will effect a final fixation of the tug T and the barge B, which, in association with the other locking members hereinbefore described, will eliminate any relative movement in any direction between the tug T and barge B.

In the operation of the form of the invention shown in FIGS. 1-7, the tug T will be driven forwardly toward the aft end of the barge B until the projection 13 of the barge B engages the undersurface of the center body 1 1 of the tug T and the shelf projections 12. The free end of the screw member 15 of the tug T is connected to the barge mounting member 16 and the nut 14 rotated thereon until the tug T and barge B are drawn together and locked in tight fore and aft relationship.

The wedge members 20, whether they be two or more, are then driven in an aftward direction by means of the operating shafts 21 into the respective recesses or channels 18 and 19 of the tug and barge until the wedge members 20 are in their outermost and locked positions. The tug T and barge B are now in an absolutely locked relationship so that any forward movement of the tug relative to the barge is prevented. Moreover, no vertical movement of the tug relative to the barge is possible and at the same time no lateral movement relative to the tug and barge is permitted. Thus, when in assembled state, the barge B and tug T will move as a single unitary member.

In the release or separation of the tug T from the barge B, the prime movers driving the operating shafts 21 are started and thereby resulting in the wedge members 20 being drawn forward toward the bow of the tug T causing an unwedging of the tag T and the barge B. The nut 14 is set into reverse rotation and this operation continued until the wedging action between the tug center body 11, the projection 13 of the barge B and the shelf portion 12 is released. The screw 15 is then disconnected from the barge mounting member 16. To complete the separation of the tug T from the barge B, the tug engines are reversed causing the tug to move aft with respect to the barge B, thus disengaging projection 13 of the barge from the center body 11 and the twin hulls 10 of the tug. This separation of the tug from the barge can be effected very rapidly by reason of this construction, which is highly desirable, particularly in the case of accidents and the like. Conversely, the tug T and barge B can be coupled in locked engagement quite easily, which is highly desirable from a standpoint of time.

While there have been described herein what are at present considered preferred embodiments of the invention, it will be obvious to those skilled in the art that modifications and changes may be made therein without departing from the essence of the invention. It is therefore to be understood that the exemplary embodiments are illustrative and not restrictive of the invention, the scope of which is defined in the appended claims, and that all modifications that come within the meaning and range of equivalency of the claims are intended to be included therein.

lclaim:

1. An integrated sea-going vessel comprising a tug boat having a pair of hulls laterally spaced from one another, a horizontally disposed shelf member connecting the bulls to one another, support means spaced from said shelf member forming a recess area therebetween along each side thereof, a cargo carrying barge unit having a horizontally disposed projection member extending rearwardly from the aft end thereof for positioning between the hulls of the tug boat and within the formed recess areas and in engagement between the shelf member and the support means in tight interfitting relationship therebetween to insure that substantially no relative vertical movement will occur between said shelf member of the tug boat and said projection member of the barge unit, wedging means positioned between the engaging portions of the tub boat and barge unit to prevent relative transverse or vertical movement therebetween, and means for locking said tug boat and said barge unit to one another to prevent relative longitudinal movement therebetween, said tug boat and said barge unit being readily disengageable from one another.

2. An integrated sea-going vessel in accordance with claim 1, wherein said support means is a shoulder portion on the inboard side of each tug hull and further includes engaging means on said projection member of said barge complementary with and positioned in the formed recess area on the side of each tug hull for insuring that substantially no relative vertical movement will occur between said shelf member of the tug boat and said projection member of the barge unit.

3. An integrated sea-going vessel in accordance with claim 1, wherein said support means includes a recessed shoulder portion at the aft end of each tug hull and below the under-surface of said shelf member of said tug boat and a notch portion is provided at the aft end of and along each side of said projection member of said barge unit, each of said notch portions being in tight interfitted relationship with the formed recess area of each tug hull.

4. An integrated sea-going vessel in accordance with claim 1, wherein the inboard sides of the hulls of the tug boat and the aft end of the hull of the barge unit have curvatures complementary with one another to insure tight, substantially flush engagement therebetween to prevent relative movement longitudinally and transversely therebetween, and is further characterized in that the top surface of said projection member of said barge unit engages the undersurface of said shelf member of said tug boat to prevent relative movement therebetween.

5. An integrated sea-going vessel in accordance with claim 1, wherein said wedge means include power means to positively drive same between the engaging portions of said tug boat and said barge unit.

6. A sea-going vessel in accordance with claim 1, wherein said wedging means includes at least a first longitudinally extending channel along the inboard side of each hull, at least a second longitudinally extending channel complementary with a first channel member along each outboard side of the projection member of said barge, a wedging member longitudinally movable within each pair of said complementary first and second channel members, and prime mover means operatively connected to each of said wedging members to move said in said channel members.

7. A sea-going vessel in accordance with claim 6, wherein each of said first channels is tapered fore and aft with the greater depth being at the forward end thereof, each of said second channels being triangular in cross-section and having a constant cross-section throughout its length, and said wedging member being generally trapezoidal shaped in cross-section and tapered longitudinally, the triangular portion of each of said wedging members being seated in the corresponding triangular shaped recess.

8. A sea-going vessel in accordance with claim 1, wherein said locking means includes a first locking assembly mounted on the top surface of said shelf member of said tug boat, a second locking assembly complementary to and operable with said first locking assembly mounted on said projection member of said barge unit, and means to drive said first and second locking assemblies into and out of engagement with one another.

9. A sea-going vessel in accordance with claim 1, wherein said tug boat is a catamaran tug boat in which said hulls are narrow and deep and the propellors therefor are large and heavy.

10. A sea-going vessel in accordance with claim 1, wherein the center of gravity thereof will be located over the mating and engaging parts of the tug boat and the barge unit whereby, when the barge unit is loaded, a downward force will be exerted. on the after end of the barge thereby insuring a stable and strong integrated vessel. 

1. An integrated sea-going vessel comprising a tug boat having a pair of hulls laterally spaced from one another, a horizontally disposed shelf member connecting the hulls to one another, support means spaced from said shelf member forming a recess area therebetween along each side thereof, a cargo carrying barge unit having a horizontally disposed projection member extending rearwardly from the aft end thereof for positioning between the hulls of the tug boat and within the formed recess areas and in engagement between the shelf member and the support means in tight interfitting relationship therebetween to insure that substantially no relative vertical movement will occur between said shelf member of the tug boat and said projection member of the barge unit, wedging means positioned between the engaging portions of the tub boat and barge unit to prevent relative transverse or vertical movement therebetween, and means for locking said tug boat and said barge unit to one another to prevent relative longitudinal movement therebetween, said tug boat and said barge unit being readily disengageable from one another.
 2. An integrated sea-going vessel in accordance with claim 1, wherein said support means is a shoulder portion on the inboard side of each tug hull and further includes engaging means on said projection member of said barge complementary with and positioned in the formed recess area on the side of each tug hull for insuring that substantially no relative vertical movement will occur between said shelf member of the tug boat and said projection member of the barge unit.
 3. An integrated sea-going vessel in accordance with claim 1, wherein said support means includes a recessed shoulder portion at the aft end of each tug hull and below the under-surface of said shelf member of said tug boat and a notch portion is provided at the aft end of and along each side of said projection member of said barge unit, each of said notch portions being in tight interfitted relationship with the formed recess area of each tug hull.
 4. An integrated sea-going vessel in accordance with claim 1, wherein the inboard sides of the hulls of the tug boat and the aft end of the hull of the barge unit have curvatures complementary with one another to insure tight, substantially flush engagement therebetween to prevent relative movement longitudinally and transversely therebetween, and is further characterized in that the top surface of said projection member of said barge unit engages the undersurface of said shelf member of said tug boat to prevent relative movement therebetween.
 5. An integrated sea-going vessel in accordance with claim 1, wherein said wedge means include power means to positively drive same between the engaging portions of said tug boat and said barge unit.
 6. A sea-going vessel in accordance with claim 1, wherein said wedging means includes at least a first longitudinally extending channel along the inboard side of each hull, at least a second longitudinally extending channel complementary with a first channel member along each outboard side of the projection member of said barge, a wedging member longitudinally movable within each pair of said complementary first and second channel members, and prime mover means operatively connected to each of said wedging members to move said in said channel members.
 7. A sea-going vessel in accordance with claim 6, wherein each of said first channels is tapered fore and aft with the greater depth being at the forward end thereof, each of said second channels being triangular in cross-section and having a constant cross-section throughout its length, and said wedging member being generally trapezoidal shaped in cross-section and tapered longitudinally, the triangular portion of each of said wedging members being seated in the corresponding triangular shaped recess.
 8. A sea-going vessel in accordance with claim 1, wherein said locking means includes a first locking assembly mounted on the top surface of said shelf member of said tug boat, a second locking assembly complementary to and operable with said first locking assembly mounted on said projection member of said barge unit, and means to drive said first and second locking assemblies into and out of engagement with one another.
 9. A sea-going vessel in accordance with claim 1, wherein said tug boat is a catamaran tug boat in which said hulls are narrow and deep and the propellors therefor are large and heavy.
 10. A sea-going vessel in accordance with claim 1, wherein the center of gravity thereof will be located over the mating and engaging parts of the tug boat and the barge unit whereby, when the barge unit is loaded, a downward force will be exerted on the after end of the barge thereby insuring a stable and strong integrated vessel. 